Hydraulic control mechanism



Aug- 19 1952 A. L.. LADO HYDRAULIC CONTROL MECHANISM 2 SHEETS-SHEET 1Filed Aug. 19, 1946 m .s a N w f v2.

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AU 19 19452 A. LADO 2,607,321

- HYDRAULIC CONTROL MECHANISM Filed Aug. 19, 194e 2 SHEETS- SHEET 2 KET:2o 25 y/////////////17/ Patented Aug. 19, 1952 `UNITED SI'l=\l'[ l5`;SPATENT OFFICE Y n, 'I v l l l2,607,321 i Y HYDRAULIC `CONTROL MECHANISM`Anthony L. Lado, Rome, N. Y., assigner, by mesne.

assignments, to Rome Grader. Corporation, RomeN. Y., a corporation ofNew Yorlr n Application August 19, 1946, Serial No.762l1g572lf i 2Claims. (Cl. 121-541..)

. l Y This invention relates to a control mechanism, particularly amechanism used tocontrol 4an object which is moved by fluid under,vpressure. An object of the invention is to provide an improved controlmechanism which fwill. easily and accurately controla movable article. g

Another object offthe inventionis to p rovide aniimproved vcontrolvmechanism which vmay be set to move an-article any desired distanceandwill permit the motion of the article to be accomplished subsequentlyjhearticle being accurately stopped'when, its' motion vhas brought it to adesired point. i l y Another object of the invention is to provide animproved control mechanism which may be used to` move an varticleselectively in either of two or more directions. f v Y y 4Another objectofthe invention is toyprovide an improved control mechanism-which maymove an article directly from one position to any other desiredpositionfwithin its range of possible motion.A v 'v- 'r Another objectof the invention is to provide an improved controlmechanism which mayreverse the motion of an article at any point in its travel. v Y -f @1Another object of the inventionA is to provide an improved controlmechanism which will be simple in construction. 1

Another object of the invention is to provide an improvedvv controlmechanism which will be easily assembled and disassembled. n 4

Another objectof ythe invention-is to provide an improved controlmechanism which will balance fluid pressures within the control. l

Other objectswill hereinafter appear. p The invention will be betterunderstood from the description of one practical' embodiment thereof,illustratedin the accompanying drawings, in whichzfi Figure l a somewhatdiagrammatic longitudinal sectional viewofa control mechanism embodyingmy invention,y this `being designed primarily for use as apart of thesteering gear of a vehicle; v n l Figure 2 is a fragmentary horizontalplan section, taken on the line II-II of Figure 1, and showing a neutralposition of the exhaust ports; Figure 3 is a fragmentary transversesectional view taken on the line III-III of Figure l; and Figures 4 to 8are longitudinal sectional views, similar to the right hand part ofFigure l but showing various positions which may be assumed by thevports in the operation of the control.

The apparatus shown in the drawings is inf 2` 1 tended for moving anarticle in either two opposed directions by varying amounts, as may bedetermined by the operator, as for instance the moving of the steeringwheel or wheels of a land vehicle, or the rudder of air or water craft,or the like. Y f

Thepartv` actuated needvnot be'V a control element; but canbe anymovable article which it may be desired tofmov'into any one of avplurality positions, but the types of control elements above mentionedfurnish a convenient example, and so are chosen for the purposes ofillustration and explanation, it being understood'that the invention isnot, however, limited to .such elements. f4

To show a very simplified control, the operator has been provided, inthe device illustrated,'with a manually movable crankl xed to an .arm 2whichis fastened to a threaded shaft 3, vas -by the clamping bolt'lli. v

The shaft is shown as supported in a bearing 5, carried by a Stationarybracket 6, the shaft being held from axial movement by a ange or collar'I engaging one side of the bearing and the hub portion of the arm 2engaging the other side thereof.

The threaded portion 8 of the shaft 3 engages the internal thread of nut9, pivotly carried at the end of a lever I0, lthe center of which isshown as pivoted at II on an extending lug I2 of the control apparatus.The upper end of the lever I0 is pivoted to a link I3 which in turn ispivoted to .a control valve sleeve I4.

Sleeve I4 is shownas cylindrical, having an open inner end and a closedouter one to which the link I3 is pivoted, and may reciprocate within acylinder I5.

The cylinderv I5 has formed in its inner'surface four recesses, whichfor clarity of illustration have been shown above and below the sleeveand to one side thereof. The recess I6 below the sleeve is connected bythe ttings and pipe I1 to a source of fluid under pressure, such as apump l? delivering oil, other liquid, air, gas or any other fluidpressure transmitting medium to the apparatus.

In the example illustrated, it is assumed that the fluid used will be ofliquid nature rather than a gaseous one, and the parts are thereforesmaller an-d heavier in their proportions because of the high pressureswhich may be practicably attained with such liquid or hydraulic media.

A-bove the sleeve are shown two spaced recesses I8 and I9 in axialalignment with each other, the former of which is-connected by fittingsand a pipe or tube 20 to the right hand end of a cylinder Within thesleeve valve I4 is a valve piston 25 sired to move the article connectedto ring 41 which is provided with two passages, shown as l peripheralgrooves 26 and 21,1-'and thisgpiston is connected xedly to a piston rod28 which` extends through packing '29., Lheldin =a vgland in the end ofcylinder I5, "into thencylinderm.

Within this last mentioned cylinder the piston rod is provided With apiston Sll carrying vpacking 3l which may be caused to travel Within a.cylinder 2| by diierentialpressure of the 'fluid 'selectively suppliedthrough pipes 20 and 22 to yThe Ypiston rod '28 'also continues through-a .cylinder'head z32 'at-f thev4 end d'of cylinder 2'I remote from thevalvemechan'ism into Lasecon'dcylinder `33 Which is 'closed on itsfurther end-by va head- 3 4.

,The cylinder head formed b y the end of valve vcylinder I5, V,the head32, andthe head 'i3-'4 are clamped together by through bolts and `nuts35'.

Within 'cylinder 33 varidfix-edto the piston -rod 28isa piston 36,provided 'jvvith packing 31, land from Vlheads' 32 and 34acommunicationwith the 'interior' of cylinderg33 is' established b ylittings Yit is desired .to move.

Returning to describe .the `control 'valve mechanism in .morefparticularity, the sleeve 'Iltis provided with a number. of ports'therethrough aslfollows:

Throughthe'bottom of vthe sleeve I4; thatis, through the portion in'alignment `withrecess I6, areports 348 and 4.9, "these .being :soYspacedI that the distance 'between them'is 'atleast equal `to .thedistance between the 'extreme Vedges 'of .grooves-,26..and'21,' thusbothgports may be closed when piston 25isinithe neutralposition shovvnin Figure '1.

.Diametrically .oppositeport v.48, and arranged kto communicateWithggroove ;26 Vand recess I8 is .a portl, -andoppositeport 49 .and'arranged Vto communicatewith groove/21 and recess I9` is :a similarpor't'l.

Between `these ports, .and Yalso 'in alignment withrecesses '|28 .and`[9,= are two .ports 52. and '53, these being spaced. so that thevover-all Adistance across them'is no greater than the 'length of-thatpart of the,piston between grooves26 and 21, .so 'that'bothjportsmay be closed'bythe central part 'of the pistonwhen the ports are ina'neutral positionfas in Figure v'1.

In longitudinal Ialignment Ywith ports 52 and 53, but oiset "to the'side 'of 'the lsleeve 4to `communicate With'recess i23,"are,respectively, two ports 254 and 55.

i The op'eration no'fsthe *device isas follows AStarting 'withthejpartsin the `position indicated in Figure 1, and Sassuming -thatitis deto the left. the operator rotates handle I to draw the nut 9toward bracket 6, thus, through the lever I0 and link I3, moving thesleeve valve I4 tothe left-say, to the position indicated in Figure 4.

It Will be apparent that this motion of the sleeve brings ports 48 and50 kintoalignment with groove 26 and brings ports"53-and55 intoalignment with groove 21, at the same time causing dports 52 and 54 tobe covered by the central Y iportionfof thepiston and ports 49 and 5I tobe covered by the left vhand end portion thereof. Thus `huid under-pressure is permitted to flow from'piper1zand-recess I 6 through port48, groove '26, port 50, recess 'I8 and pipe 20 to the righthandgendofcylinder 2I to move piston 30 to th left. 'i l Simultaneously,the passage from the left hand end of cylinder 2I through pipe 22permits -the Vdischarge of vfluidthrciughrecess .1139, .ports '53,groove'21,port55,andpipez24 to the receiving tank lor sump C F, fia-huefpermitting `the" leftvvard movementl ofpistonil.

The motion rofl-piston .'34, of course, Y'moves piston 3B 1li-n thesame' direction, :and fsowfdrces and Vconnection article. Y -Y Y This`motion of fthe fpistons :continues iuntil theparts reach the positionsindicated in Figure 5, in which the piston valve 25 has moved until itslright hand V end againv covers :ports 48 .and .54,

its 'central portioncovers ports52, 53,*'54 and .155,

and its left handfen'cl still covers ports 49"*and 5I. In this position,no rliiidfcan now-through vthe Lcontrol V:and the fparts `l"are brought`to rest.

In Figure f-'6, the Vv"sleeve 'hasbeen moved i in the oppositedirection-itc v=the Iright-fitoA a 'position *beyond thatA Which'it hadroccupied-at itsmore or less central original position of Figurelfand'it 'isV apparent lthatiiluidmay -now 'f'floW' fromI pipe I1 and Vrecess-I 6,through'port-4 9,-groove'f2r1, port 5I, recess I`9,andpipe @22 Ito'the left hand end of cylinder 2|, and that iluid may now be-dis'-ycharged from' theright hand-endfofthisY cylinder *throughV pipeZ Il,recessI-, portl5'2,y groove'26; port 54, recess 23, and pipe 24 `-tothes`ump T. The uid'novv Will'movepiston 30, together With pis- Ytons 35and43 to-the-rig`ht -untilthepiston -valve 25 hasreached'thelpositionfshownfin Figure 7, wl'iere once -`againaall 'theports are closed.

'Figure 18' shows"atsetting of the sleeve f valve to move the pistonsstill mvfarther -to Athe rightf--vto theirfurthest distance A"in thisdirection. The :communications :established and directions of 'motionare thesamefaszinfligure.

VEven where-'the sleeve has -`been `Inovedtofthe extreme position shownin Figure 48, Where ports 52iand' 53 V'are V'both'incommunication 4withrecess I8, thefparts function "correctly :because the centralporticn :ofthe piston *'25 covers port 54 `so long-as groove-26 isin'commun'ication Withipo'rts 52 and 54, so that there can be nobypassingof the fluid lWhich would interferewiththe -opera tion. y

"To return the parts v`to their original :position it isonly-necessary@tot-returnthesleeve vvalve to its initialr position,fas-inl Figure '1,1When the fluid passesthrough-the -various' passages:asit d-id in Figure 4, until/'thefpistonf25resumes its original neutralposition.

'From the aboveitfis-:apparent:that-ianyfmotion "of the `t's'leeve:valve "Will Vcause a corresponding motion of the several pistons, theparts always coming to rest when piston valve 25 is in such a positionthat its ends cover ports 48, 49, 50 and and its central portion coversports 52, 53, 54 and 55 and that the amount of motion imparted to piston43 therefore is directly proportional to the amount of motion impartedto the sleeve I4.

The actual distance travelled by piston 43, of course, may be varied bythe proportioning of the diameters of the cylinders 33 and 42, while theforce which as applied can be determined by the areas of the pistons inthese two cylinders, as well as that in cylinder 2|, and the pressure ofthe uid supply.

Both the piston valve 25 and the sleeve I4 are so arranged that allpressures acting upon them are balanced, so that the sleeve may be movedby any motion which is suiicient to overcome the friction between thepiston 25, the sleeve I4, and the cylinder I5. Also, the ports areopened and closed somewhat gradually so that the smoothness of operationis assured.

It will be observed that if the motions of the sleeve I4 and of thepiston valve 25 are very short, ports 52 and 53 can be merged into asingle port, and so likewise can ports 54 and 55, but this can only bedone when the length of the combined port will be of less length thanthe distance between recesses I8 and I9, because otherwise iiuid will beby-passed between these recesses interfering with the operation of theapparatus.

While I have described the illustrated embodiment of my invention insome particularity, ob-

viously many other embodiments, modifications and variations will occurto those skilled in this art, and I do not. therefore, limit myself tothe precise details shown and described herein, but claim as myinvention all embodiments, modications and variations coming within thescope of the appended claims.

I claim:

1. An hydraulic control device comprising a source of fluid underpressure, a cylinder, a load moving piston movable therein, a piston rodxed to the piston and carryingv a cylindrical valve part provided withtwo annular grooves, a sleeve slidably fitting the exterior of the valvepart carried by the piston rod and having ports therethrough angularlydisposed about the sleeve, a fixed cylindrical casing slidably receivingthe exterior of the sleeve and having four recesses on its interiorwhich may selectively be brought into alinement with the ports throughthe sleeve by the axial movement of said sleeve, one said recess beingconnected to the discharge side of the source of fluid under pressure,another recess being connected to the intake side of the source of fluidunder pressure, a third recess being connected to one end of saidcylinder, the fourth recess being connected to the opposite end of saidcylinder, and positive connections between the piston and its load, saidtwo annular grooves being selectively registerable with certain of saidsleeve ports and certain of said recesses to effect a movement of saidpiston rod in a selected axial direction.

2. An hydraulic control device comprising a source of fluid underpressure, a cylinder, a load moving piston movable therein, a piston rodconnected into the piston and extending beyond the cylinder, acylindrical valve part fixed to said piston rod and having two annulargrooves, a tubular sleeve slidably fitting said valve part and providedwith ports therethrough annularly spaced about the Sleeve, a fixed valvecylinder slidably receiving the sleeve and having two axially alignedrecesses connected with the opposite ends of the cylinder, the valvecylinder having two additional interior recesses out of axial alignmentwith each of the two first mentioned recesses and with each other, andconnections between one of the last mentioned recesses and the outletside of the source of fluid under pressure and between the other of thelast mentioned recesses and the intake side of the said source of fluidunder pressure, said two annular grooves being selectively registerableby relative movement of said sleeve and said cylindrical vvalve part onsaid piston rod, with certain of said recesses to eiiect an axialmovement of said piston rod.

ANTHONY L. LADO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 160,327 Hutchison Mar. 2, 1875591,768 Kaselowsky Oct. 12, 1897 689,186 Heisler Dec. 17, 1901 863,405Koelkebeck Aug. 13, 1907 2,038,272 Ernst Apr. 21, 1936 2,140,037 SwisherDec. 13, 1938 2,221,150 Rebeski Nov. 12, 1940 2,363,179 Harrington Nov.21, 1944 2,374,545 Ingres Apr. 24, 1945 2,380,575v Brown July 31, 1945

